1. Field
The present disclosure relates to an acoustic wave filter and a method for manufacturing the same.
2. Description of Related Art
In a band pass filter, obtaining an appropriate band is an important feature that affects the application of the filter. Such a band may be obtained by adjusting a resonant frequency of a resonator, for example, a series resonance frequency (Fs) and a parallel resonance frequency (Fp).
One method for adjusting the resonant frequency is by physically decreasing a thickness of the resonator by performing a trimming process on a wafer after manufacturing the resonator.
Because the trimming process generally includes an etching step to decrease a thickness of the resonator to tune the resonant frequency of the resonator, it may be difficult to only trim a separate filter (i.e., a separate resonator). Thus, undesirable effects such as dispersion may occur, depending on a machining process condition.
Moreover, a fabrication processes such as photolithography may be required for performing the selective etching steps in trimming the resonator. This may undesirably degrade a yield while manufacturing the filter.